/*
 * Copyright 2017-2019 The OpenTracing Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
 * in compliance with the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License
 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */

package io.opentracing.contrib.grpc;

import io.grpc.ServerInterceptor;
import io.grpc.ServerInterceptors;
import io.grpc.stub.StreamObserver;
import io.grpc.util.MutableHandlerRegistry;
import io.opentracing.contrib.grpc.gen.GreeterGrpc;
import io.opentracing.contrib.grpc.gen.HelloReply;
import io.opentracing.contrib.grpc.gen.HelloRequest;
import io.opentracing.util.GlobalTracer;

class TracedService {

  static void addGeeterService(MutableHandlerRegistry registry) {
    registry.addService(new GreeterImpl());
  }

  static void addGeeterService(MutableHandlerRegistry registry, ServerInterceptor... interceptors) {
    registry.addService(ServerInterceptors.intercept(new GreeterImpl(), interceptors));
  }

  private static class GreeterImpl extends GreeterGrpc.GreeterImplBase {

    @Override
    public void sayHello(HelloRequest req, StreamObserver<HelloReply> responseObserver) {
      // verify that there is an active span in case of using GlobalTracer:
      if (GlobalTracer.isRegistered() && GlobalTracer.get().activeSpan() == null) {
        throw new RuntimeException("no active span");
      }

      HelloReply reply = HelloReply.newBuilder().setMessage("Hello " + req.getName()).build();
      responseObserver.onNext(reply);
      responseObserver.onCompleted();
    }
  }
}
